Mesorhizobium terrae sp. nov., a novel species isolated from soil in Jangsu, Korea.

Abstract

A gram-negative, white-pigmented, aerobic, rod-shaped bacterium, designated as strain NIBRBAC000500504T, was isolated from soil in Jangsu, Korea. Optimal growth of this strain was observed at 25 °C, pH 7.0, and in the presence of 0% (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain NIBRBAC000500504T belonged to the genus Mesorhizobium and was closely related to Mesorhizobium shangrilense LMG 24762T (98.3% sequence similarity), Mesorhizobium australicum LMG 24608T (98.2%), Mesorhizobium qingshengii LMG 26793T (98.1%), Mesorhizobium ciceri ATCC 51585T (98.0%), Mesorhizobium loti DSM 2626T (98.0%), Mesorhizobium sophorae LMG 28223T (97.9%), Mesorhizobium waitakense LMG 28227T (97.8%), and Mesorhizobium cantuariense LMG 28225T (97.8%). Next-generation sequencing analysis indicated that the genome of strain NIBRBAC000500504T comprised a circular chromosome (5,731,152 bp, G+C content: 63.26%) and a plasmid (293,638 bp, G+C content: 61.39%) with 5672 coding sequences, 50 tRNAs, and 6 rRNAs. The major respiratory isoprenoid quinone was Q10; the major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, and phosphatidylcholine; the major fatty acids were summed feature 8 (comprising C18:1 ω7c/C18:1 ω6c), C19:0 cyclo ω8c, C16:0, and C18:1 ω7c 11-methyl; and the G+C content of the genomic DNA was 62.9 mol%. The DNA-DNA relatedness values between NIBRBAC000500504T and its closest type strains were low. On the basis of these polyphasic taxonomic data, it is proposed that strain NIBRBAC000500504T represents a novel species of the genus Mesorhizobium, with the type strain being NIBRBAC000500504T (= KCTC 72278T = JCM 33432T).